### All AP Statistics Resources

## Example Questions

### Example Question #1 : How To Do Cluster Sampling

A researcherer wants to study the effectiveness of a certain curriculum program on kids' math scores, so she wants to implement the curriculum with kids in grades 2 to 4 to see if their scores significantly improve. To do so, she wants to try Random Cluster Sampling. How can she do this?

**Possible Answers:**

Find a list of all elementary schools in the state and then only look at schools with weak math programs before selecting which schools to run the experiment in.

Randomly select an elementary school from the entire list of elementary schools in the country

Find a local elementary school and perform the experiment there.

Select a "cluster" of schools in a local area.

Randomly select an elementary school in the country and ask the principal to recommend other schools that would be interested in participating.

**Correct answer:**

Randomly select an elementary school from the entire list of elementary schools in the country

Random sampling is a method in which every individual has an equal opportunity of being randomly chosen to participate in a study.

Cluster random sampling entails choosing from pre-formed "clusters"-- such as schools or hospitals-- and randomly selecting one of the clusters.

### Example Question #2 : How To Do Cluster Sampling

Kevin would like to find out what type of car is the most popular among residents in his neighborhood. There are 25 streets in his neighborhood and each street has approximately 12 houses on it. He would like to survey at least 120 houses before making a conclusion.

Which of the following is an example of random cluster sampling in Kevin's neighborhood?

**Possible Answers:**

Kevin could divide his neighborhood into five homogeneous groups and choose one group at random to survey houses within

Kevin could survey five houses at random on every single street in his neighborhood

Kevin could number each house from 1 to 300 and then randomly select 120 houses to survey using a random number generator

Kevin could divide his neighborhood into five different groups and select 25 houses at random from each group to survey

Kevin could survey every third house in his neighborhood

**Correct answer:**

Kevin could divide his neighborhood into five homogeneous groups and choose one group at random to survey houses within

In order for cluster sampling to be present, the entire population must be divided into homogeneous groups (known as clusters). For sampling purposes in this problem, clusters must be chosen as a simple random sample. There is only one answer choice that fits this pattern.

Certified Tutor